Ruthless Vows Audiobook & Text to Speech Guide (2026) — Rebecca Ross's Duology Finale
Ruthless Vows — Rebecca Ross
First published: December 26, 2023 · Wednesday Books / Macmillan
Pages: 420 (hardcover)
Goodreads: 3.98★ (431K+ ratings) · view
Audiobook runtime: 14h 6m · Narrators: Alex Wingfield + Rebecca Norfolk (dual-cast continuing from Divine Rivals)
Series: Letters of Enchantment book 2 · Duology finale — complete arc
Prerequisites: Divine Rivals (book 1, 10h 30m)
The duology finale. Don't start here — Divine Rivals (book 1) is the required starting point →
Ruthless Vows is Rebecca Ross's December 2023 Wednesday Books / Macmillan release — the second and final book of the Letters of Enchantment duology. Opening from Divine Rivals's war-separation cliffhanger, the book follows Iris and Roman across opposing sides of the gods' war, negotiating captivity, coerced cooperation, and the stakes of separation versus reunion. The dual-narrator Alex Wingfield + Rebecca Norfolk production continues from book 1 with vocal continuity. The 3.98★ Goodreads rating and 431,000+ ratings reflect both finale-polarization and the duology's sustained popular following.
This guide covers the 14h 6m runtime, duology-binge math, dual-cast continuity, and every free / paid path.
Why You Should Read Divine Rivals First
Ruthless Vows is the second half of a tightly-connected arc. The gods-war, Iris + Roman correspondence foundation, the Five Gods pantheon, and the Trench Era setting are established in Divine Rivals and carried forward in Ruthless Vows without re-introduction.
For listeners considering skipping Book 1:
- Major Divine Rivals cliffhanger is resolved in Chapter 1 of Ruthless Vows (unavoidable spoiler for book 1)
- Iris + Roman's relationship dynamic is assumed, not re-established
- Gods-war setup has book-1 context that book-2 references continuously
Recommendation: read Divine Rivals (10h 30m) → first, then return to this Ruthless Vows guide. The combined duology is ~24h 36m total — roughly one Fourth Wing runtime for full-arc closure.
Three Listening Modes
- Duology-completion mode — you've finished Divine Rivals and want closure. Ruthless Vows delivers the arc payoff. Primary mode.
- TV-adaptation prep mode — you're preparing for Letters of Enchantment TV release or season 2. Re-listening both books in sequence before show drops enables book-vs-show comparison. CastReader own-forever is economical for this use case.
- War-arc fantasy mode — you enjoy the separation-and-reunion-through-war structural pattern (The English Patient, Atonement, Code Name Verity). Ruthless Vows shifts more in this direction than Book 1's workplace-rivals-to-romance framework.
Platform-by-Platform Breakdown
| Platform | Cost | Narration | Best for |
|---|---|---|---|
| Audible credit | 1 credit | Wingfield + Norfolk (dual-cast) | Good credit value at 14h 6m |
| Audible à la carte | ~$17-22 | Wingfield + Norfolk | Single-purchase binge continuation |
| Audible Plus | Check rotation | Wingfield + Norfolk | Sometimes included |
| Libby (free library) | Free (1-4 wk wait) | Wingfield + Norfolk | Best free path |
| Hoopla | Free, instant | Varies | Good availability |
| Spotify Audiobooks | Fits 15h free/mo (tight) | Wingfield + Norfolk | Covered by monthly hours |
| Kindle + CastReader | $9-12 ebook + free AI TTS | AI (Kokoro), single-voice | Cheapest own-forever |
Option A — Audible (Dual-Cast Continuity Canonical)
The Wingfield + Norfolk dual-narrator continuation from Divine Rivals is the canonical first-listen path. Character-voice continuity across the duology is a material audiobook strength — starting fresh with different narrators would break the pattern. Credit value at 14h 6m is good; à la carte ~$17-22 is reasonable for the finale book of an established duology.
Option B — Libby (Best Free Path)
Libby waits for Ruthless Vows in April 2026 are 1-4 weeks — paralleling Divine Rivals availability. Coordinated duology borrowing plans: borrow Divine Rivals first, finish reading, then borrow Ruthless Vows (total elapsed: 2-8 weeks). For listeners with flexible timeline, Libby covers the full duology free with dual-cast production.
Option C — Kindle + CastReader (Own-Forever Re-Listen Path)
For re-listens and TV-adaptation-prep:
- Audible 2 credits ≈ $30 equivalent (duology, dual-cast)
- Libby: free but borrow cycle per re-listen
- Kindle duology $15-22 + free CastReader AI TTS = own forever, unlimited re-listens
Setup (Ruthless Vows-specific):
- Buy Kindle Ruthless Vows ($9-12; Wednesday Books promotional discounts apply)
- Open in Kindle Cloud Reader
- Install CastReader Chrome or Edge
- Press play — AI narration + paragraph highlighting + auto-page-turn across 420 pages
Important tradeoff: the duology's dual-cast voice-mapping (Wingfield = Roman, Norfolk = Iris) is first established in Divine Rivals. CastReader AI TTS's single-voice default loses this mapping, but after first-listen has anchored the characters, re-listens can tolerate single-voice AI without confusion.
Option D — Spotify Audiobooks (Tight Monthly Fit)
At 14h 6m, Ruthless Vows fits within Spotify Premium's 15 free audiobook hours per month, leaving 54 minutes of buffer. Single-month coverage viable; not enough buffer for same-month Divine Rivals re-listen.
Letters of Enchantment Duology Binge Math
| Binge strategy | Listening cadence | Total elapsed | Speed setting |
|---|---|---|---|
| Weekend binge | Back-to-back days | 2-3 days | 1.5x (~16h 24m compressed) |
| Weekly binge | 3-4h per day | 7-10 days | 1.0-1.25x (~24-25h) |
| Commute binge | 30-60min/day | 3-6 weeks | 1.0-1.25x |
| Audible 2-credit efficient | First-listen only | Varies | Production-optimal |
Speed tuning: 1.25x works for both books uniformly; 1.5x is aggressive but viable for second re-listen where content is familiar.
TTS Settings for Ruthless Vows on CastReader
| Setting | Recommendation | Why |
|---|---|---|
| Base voice (Iris POV) | Warm mid-register female, YA-adjacent | Continuity with Divine Rivals voice mapping |
| Roman POV chapters | Mid-register male, literary-journalist tone | Rival-to-lover continuation |
| War-separation scenes | Slower speed, emphasis on internal monologue | Separation-arc register shift |
| Speed | 1.0x for internal / separation; 1.25x action and front-line chapters | Scene-type pacing |
| Highlighting | On | War-era + duology-specific terminology |
| Auto page turn | On | 420 pages |
| Pronunciation overrides | Iris Winnow, Roman Kitt, Enva, Dacre, Oath Gazette, Trench-era place names | Series-specific vocabulary continuity |
| Send to Phone | For 14h 6m + full-duology re-listen | Cross-device war-separation-to-reunion continuity |
Content Considerations
Ruthless Vows is YA-adjacent / new-adult war romantasy. Unabridged on audio:
- Romance register: moderate — emotional intimacy, slow-burn reunion, less explicit than adult romantasy
- Violence: intensified war setting (WWI-styled Trench Era), on-the-page front-line coverage, PTSD-adjacent reality, character deaths
- Grief / family trauma: Iris brother-loss continuation, Roman identity resolution
- Dark themes: war devastation, coerced cooperation, captivity, potential permanent separation
Slightly heavier content than Divine Rivals due to war-arc escalation; mixed-company listening with discretion on peak war-peril and emotional-separation scenes. Generally less explicit / headphone-dependent than adult romantasy flagships.
Buying & Borrowing Links
- Audible edition — $17-22 or 1 credit
- Libro.fm — indie-bookstore support
- Libby / Hoopla — free with library card, short wait
- Spotify Audiobooks — tight fit in monthly free hours
- Kindle edition — $9-12 for own-forever
- Wednesday Books / Macmillan — publisher page
- Rebecca Ross author page — author site
Related Reading
- Divine Rivals — Letters of Enchantment book 1 (required prerequisite)
- Fourth Wing — adult romantasy flagship contrast
- Iron Flame — ongoing-series sophomore novel contrast
- A Court of Mist and Fury — series-sophomore romantasy peer
- The Summer I Turned Pretty — YA-crossover romance peer
- The Seven Husbands of Evelyn Hugo — literary-register emotional arc peer
- Listen to Kindle Cloud Reader — CastReader OCR bypass
- Audible Alternative Free — duology-binge listening economics
Fourteen hours six minutes of duology-finale war romantasy — closing Iris and Roman's arc through separation, captivity, and reunion stakes. Ruthless Vows completes Rebecca Ross's Letters of Enchantment with the dual-narrator Wingfield + Norfolk vocal continuity from Divine Rivals intact. Audible for the canonical dual-cast first-listen, Libby for short-wait free access, Kindle + CastReader for own-forever re-listens and TV-adaptation prep across the full 24h 36m duology. Choose based on whether this is first-listen (production-optimal path) or re-listen (cost-optimal path) — but read Divine Rivals first.
